A conventionally known tool includes any one of various composite members produced by providing, on the outer surface of a member serving as a core member, a cover layer made of a material different from that for the core member. Examples of such a known tool include various tools such as a medical guide wire used in intravascular treatment, an electrode wire used in electric discharge machining, and a heat insulating pipe.
The medical guide wire used in intravascular treatment is produced by covering the surface of a linear metal core member with a resin and applying hydrophilization treatment to the surface of the resin (e.g. Patent Document 1). Various techniques can be adopted for covering the surface of the core member with a resin. For example, a known method includes immersing the linear core member in a reservoir containing a resin generated in a liquid form at high temperature and then cooling to form a resin layer on the surface of the linear core member.
The electrode wire used in electric discharge machining is produced by covering the periphery of a core member made of Cu alloy with a Cu—Zn alloy layer, for example (e.g. Patent Document 2). A method for plating with Zn the surface of the core member is known as a technique for forming the Cu—Zn alloy layer on the surface of the core member.
There are heat insulating pipes in various forms. For example, a heat insulating pipe used for preventing heat radiation and supplying liquid is produced by winding a heat insulating member in a sheet shape around the outer peripheral surface of a metal pipe.